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Thermal energy storage using common phase change materials (PCMs) usually suffers from a long time consumption, uneven temperature, and low efficiency. An electromagnetic induction heating method w...

Polyphosphate (poly-P) is a chain of phosphate moieties linked through high-energy phosphoanhydride bond, and it plays an important role in regulatory functions in prokaryotic cells. Isotope effect...

A porous polyimide (PI) membrane is successfully prepared via nonsolvent-induced phase separation with two porogens: dibutyl phthalate and glycerin. The as-prepared uniform porous PI membrane shows excellent separator properties for lithium-ion batteries (LIBs). Compared with the commercial polyethylene (PE) separator, the PI separator exhibits significant thermal stability, better ionic conductivity, and wettability both in carbonate and ether electrolytes for LIBs. The battery coin-cells assembled with the PI separator is more robust and still works even after heating at 140 °C for 1 h, while the cells with the commercial PE separator could not charge any more due to the shrinkage of the PE under the same condition.

Widening the operational voltage window (OVW) of electrolytes has long been attracting researchers’ attention as an effective solution for improving the energy density of supercapacitors (SCs). However, the application of commercial cellulose separators in SCs under high voltage is impeded because of the hygroscopic property of hydroxyl functional groups and high self-discharges. Herein, the dielectric materials poly(vinylidene fluoride-co-hexafluoropropylene) PVDF-HFP and TiO2 are employed to modify the surfaces of cellulose separators, which has improved the rate (100% capacitance retention at 20 A g−1) and cyclic (over 83% capacitance retention after 10000 cycles) performance of SCs significantly. In addition, the OVW of the organic electrolyte is widened from 2.7 V to 3.8 V. The possible mechanism underlying the function of dielectric materials in SCs is discussed by establishing a model and performing inferential calculation.

Immunotherapy has achieved efficacy for advanced colorectal cancer (CRC) patients with a mismatch-repair-deficient (dMMR) subtype. However, little immunotherapy efficacy was observed in patients with the mismatch repair-proficient (pMMR) subtype, and hence, identifying new immune therapeutic targets is imperative for those patients. In this study, transcriptome data of stage III/IV CRC patients were retrieved from the Gene Expression Omnibus database. The CIBERSORT algorithm was used to quantify immune cellular compositions, and the results revealed that M2 macrophage fractions were higher in pMMR patients as compared with those with the dMMR subtype; moreover, pMMR patients with higher M2 macrophage fractions experienced shorter overall survival (OS). Subsequently, weighted gene co-expression network analysis and protein–protein interaction network analysis identified six hub genes related to M2 macrophage infiltrations in pMMR CRC patients: CALD1, COL6A1, COL1A2, TIMP3, DCN, and SPARC. Univariate and multivariate Cox regression analyses then determined CALD1 as the independent prognostic biomarker for OS. CALD1 was upregulated specifically the in CMS4 CRC subtype, and single-sample Gene Set Enrichment Analysis (ssGSEA) revealed that CALD1 was significantly correlated with angiogenesis and TGF-β signaling gene sets enrichment scores in stage III/IV pMMR CRC samples. The Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm and correlation analysis revealed that CALD1 was significantly associated with multiple immune and stromal components in a tumor microenvironment. In addition, GSEA demonstrated that high expression of CALD1 was significantly correlated with antigen processing and presentation, chemokine signaling, leukocyte transendothelial migration, vascular smooth muscle contraction, cytokine–cytokine receptor interaction, cell adhesion molecules, focal adhesion, MAPK, and TGF-beta signaling pathways. Furthermore, the proliferation, invasion, and migration abilities of cancer cells were suppressed after reducing CALD1 expression in CRC cell lines. Taken together, multiple bioinformatics analyses and cell-level assays demonstrated that CALD1 could serve as a prognostic biomarker and a prospective therapeutic target for stage III/IV pMMR CRCs.

The mechanism of long-distance electron transfer via redox-active particulate natural organic matter (NOM) is still unclear, especially considering its aggregated nature and the resulting low diffusivity of its quinone- and hydroquinone-containing molecules. Here we conducted microbial iron(III) mineral reduction experiments in which anthraquinone-2,6-disulfonate (AQDS, a widely used analogue for quinone- and hydroquinone-containing molecules in NOM) was immobilized in agar to achieve a spatial separation between the iron-reducing bacteria and ferrihydrite mineral. Immobilizing AQDS in agar also limited its diffusion, which resembled electron-transfer behavior of quinone- and hydroquinone-containing molecules in particulate NOM. We found that, although the diffusion coefficient of the immobilized AQDS/AH

Redox-active organic molecules such as anthraquinone-2,6-disulfonate (AQDS) and natural organic matter (NOM) can act as electron shuttles thus facilitating electron transfer from Fe(III)-reducing bacteria (FeRB) to terminal electron acceptors such as Fe(III) minerals. In this research, we examined the length scale over which this electron shuttling can occur. We present results from agar-solidified experimental incubations, containing either AQDS or NOM, where FeRB were physically separated from ferrihydrite or goethite by 2 cm. Iron speciation and concentration measurements coupled to a diffusion-reaction model highlighted clearly Fe(III) reduction in the presence of electron shuttles, independent of the type of FeRB. Based on our fitted model, the rate of ferrihydrite reduction increased from 0.07 to 0.19 μmol d-1 with a 10-fold increase in the AQDS concentration, highlighting a dependence of the reduction rate on the electron-shuttle concentration. To capture the kinetics of Fe(II) production, the effective AQDS diffusion coefficient had to be increased by a factor of 9.4. Thus, we postulate that the 2 cm electron transfer was enabled by a combination of AQDS molecular diffusion and an electron hopping contribution from reduced to oxidized AQDS molecules. Our results demonstrate that AQDS and NOM can drive microbial Fe(III) reduction across 2 cm distances and shed light on the electron transfer process in natural anoxic environments.

Low energy density hinders the development of supercapacitors in the market of large hybrid power equipment and electric vehicles that demand much higher energy density. Herein, we conduct a facile and environmentally friendly method to modify the electrodes of supercapacitors through coating a dielectric thin film by atomic layer deposition (ALD) technique, which profoundly improves the electrochemical performance of the electrodes. In specific, the gravimetric capacitance of the ALD-Ti modified electrodes is characterized by 35% significant promotion comparing to the commercialized pristine counterparts, and the operational voltage window of the ALD treated electrodes can expand to 3.5 V using organic electrolyte with remarkable capacitance retention (over 83%) even after 20000 cycles. Besides, appropriate models are established to discuss the detailed charge storage mechanism and possible reasons for good stability of modified electrodes under higher operational voltage. Moreover, the excellent rate and cycling performance of ALD modified electrodes in flexible electrochemical double-layer capacitor (EDLCs) at the bending state substantiates the application superiority of ALD modified electrodes in flexible devices. The unusual combination of charge storage mechanisms of dielectric capacitors and EDLCs established in our work represents specific properties in great need for energy storage applications.

Nanofiller-tailored stereocomplexation signifies a promising and feasible pathway to develop heat-resistant poly(lactic acid) (PLA) materials. However, this pathway is thwarted by the potential adverse environmental issues of traditional nanofillers and the challenges in facilitating the nanofiller dispersion and selective formation of stereocomplex crystals (SCs). Here we unravel a microwave-assisted approach to exploit biobased quantum dots (QDs) featuring excellent capability to preferably nucleate PLA SCs. The combination of ultrasmall dimension and high oxygenation degree of QDs conferred intimate interactions with stereocomplexed PLA chains, readying complete exfoliation and uniform dispersion of QDs to promote stereocomplexation. The well-dispersed QDs provided perfect UV shielding for PLA composites, while sustaining high transmission to visible light comparable to pure PLA. Strong interfacial interactions and high concentration of SCs were created around the nanoscale surfaces of QDs, accounting ...

Understanding phosphorus (P) availability and its control on eutrophication in the Chesapeake Bay is complicated by variable sources and biogeochemical transformations. We investigated seasonal and spatial variability in P limitation and biological utilization in the bay using nutrient stoichiometry (of both dissolved and particulate forms), phosphate oxygen isotope ratios, and alkaline phosphatase activity at 3 sites along the salinity gradient. We demonstrate that particulate nutrient ratios can be used as indicators of nutrient limitations in the bay, and suggest strong seasonal and spatial variability in P availability: the surface water is P limiting in spring, but this condition is alleviated in summer and in the deeper waters. Variability in P limitation is well reflected in the trends of phosphate oxygen isotope composition (δ18OP), with values approaching isotopic equilibration under P limiting conditions, suggesting rapid biological P turnover. δ18OP values suggest multiple phosphate sources, including remobilization of terrestrial inorganic P phases, and remineralization of organic P. P from both sources is sufficiently cycled by organisms, suggested by the extensive equilibrium oxygen isotope exchange. Our results further suggest high P utilization in the deeper euphotic zone where nutrients are abundant, raising caution on studying nutrient availability and limitation only in the surface water.

Particulate phosphorus (PP) in the water column is an essential component of phosphorus (P) cycling in the Chesapeake Bay because P often limits primary productivity, yet its composition and transformation remain undercharacterized. To understand the mobilization of PP and P sequestration in the water column, we studied seasonal variations in particulate organic and inorganic P species at three sites in the Chesapeake Bay, using chemical extractions, 1-D (31P) and 2-D (1H-31P) NMR spectroscopies, and electron microprobe analyses. Our results suggest that an average of 9% and 50% of water column PP was recycled in shallow and deep sites, respectively, primarily through remineralization of organic P, which was 3 times higher than Fe-bound P remobilization. P recycling efficiency was highest in the warm and anoxic seasons. Organic P compositions and concentrations responded strongly to seasonal and redox variations: orthophosphate monoesters and diesters, and diester-to-monoester ratios (D/M) decreased with depth; both esters and D/M ratios were lower in the anoxic waters in July and September. In contrast, pyrophosphate concentration increased with depth and polyphosphate concentration was high in anoxic seasons. Our analyses suggest the presence of Ca-phosphate minerals (Ca-P) in the water column but with concentrations comparable to sediment Ca-P. It is unclear, however, whether authigenic precipitation occurred in the water column or resuspended from sediments. Overall, these results reveal the dominance of internal P cycling particularly via organic P remineralization and controlling P availability in the water column of the Chesapeake Bay.

Soil organic matter (SOM), including humic substances (HS), is redox-active, can be microbially reduced, and transfers electrons in an abiotic reaction to Fe(III) minerals thus serving as electron shuttle. The standard procedure to extract HS from soil and separate them into humic acids (HA) and fulvic acids (FA) involves alkaline and acidic solutions potentially leading to unwanted changes in SOM chemical and redox properties. To determine the effects of extraction conditions on the redox and electron shuttling properties of SOM extracts, we prepared HS and SOM extracts from a forest soil applying either a combination of 0.1 M NaOH and 6 M HCl, or water (pH 7). Both chemical extractions (NaOH / HCl) and water extractions were done in separate setups under either oxic or anoxic conditions. Furthermore, we applied the NaOH / HCl treatment to a subsample of the water-extracted-SOM. We found that soil extraction with NaOH lead to ca. 100 times more extracted C and the extracted HS had 2–3 times higher electron exchange capacities (EEC) than SOM extracted by water. For water-extracted SOM, anoxic extraction conditions lead to about 7 times more extracted C and 1.5 times higher EEC than under oxic extraction conditions. This difference was probably due to the occurrence of microbial reduction and dissolution of Fe(III) minerals in the soil during the water extraction at neutral pH and the concomitant release of Fe(III) mineral-bound organic matter. NaOH / HCl treatment of the water-extracted SOM lead to 2 times higher EEC values in the HA isolated from the SOM compared to the water-extracted SOM itself, suggesting the chemical treatment with NaOH and HCl caused changes of redox-active functional groups of the extracted organic compounds. Higher EEC of extracts in turn resulted in a higher stimulation of microbial Fe(III) mineral reduction by electron shuttling, i.e. faster initial Fe(III) reduction rates, and in most cases also in higher reduction extents. Our findings suggest that SOM extracted with water at neutral pH should be used to better reflect environmental SOM redox processes in lab experiments and that potential artefacts of the chemical extraction method and anoxic extraction condition need to be considered when evaluating and comparing abiotic and microbial SOM redox processes.

Advance selling helps retailers who often face a newsvendor problem to reduce demand uncertainty. With the development of e-commerce and promotion, retailers are no longer limited to a single advance selling strategy. Random rewards promotion becomes increasingly easy to apply with the support of network and information technology. Advance selling strategy considering random rewards is favoured by retailers because it not only caters to the psychological needs of strategic consumers but also helps retailers reduce the uncertainty of demand. The advance selling strategy considering random rewards is an optimization model that is established on the basis of single advance selling strategy model. The objective function of the model is retailer’s total profit. The random rewards mechanism is modelled according to the actual situation. The expected utility of consumers’ random rewards adopts a power function of risk aversion type based on strategic consumer reactions. This study analytically examines the optimal total profit of a retailer under the two advance selling strategy models and finds that there is threshold that determines whether an advance selling strategy considers random rewards. In addition, we compare and analyse the advance selling price and consumer utility under the two strategies. Results comparison reveals that the difference between the amount of discount and the size of the winning prize’s expected utility under single advance selling strategy determines whether the advance selling price adopts a discount sales strategy. Numerical analysis further validates the results of the study.

By virtue of its high specific surface area and low tortuosity for ionic storage and transportation, holey graphene has come to be regarded as a promising material for energy storage devices, such as lithium ion batteries, and supercapacitors. For practical applications, a scalable and green preparation method for holey graphene is required. This work proposes a facile preparation method for holey graphene by simply microwaving pristine graphene in air. Compared with previous scalable methods, this method exhibits much greater efficiency, reducing the preparation time from hours to minutes. The mechanism underlying the microwave irradiation-induced formation of nanosized holes involves the interaction between microwaves, electrons, oxygen in air, and carbon atoms in the defect areas of the graphene. The size, density, and distribution of holes can be controlled by tuning the microwave irradiation time and oxygen concentration. Used as a hybrid conductive agent, the as-prepared holey multilayer graphene increases capacitance retention to 96.25% at high current density (8 A g−1), and 96.48% in long cycles (1 A g−1 and 10 000 cycles).

The fate and toxicity of zinc oxide nanoparticles (ZnO NPs) in nature are affected by solution chemistry such as pH, anions, and natural organic matter (NOM). Inorganic polyphosphates are environmentally ubiquitous phosphorus (P) species that may change the speciation and environmental fate of ZnO NPs. In this study, the interactions of polyphosphates with ZnO NPs and the impacts on ZnO NP dissolution and transformation were investigated and compared with orthophosphate (P1). The results revealed that pyrophosphate (P2), tripolyphosphate (P3), and hexametaphosphate (P6) enhanced whereas P1 inhibited the dissolution of ZnO NPs. In addition, P1, P2, and P3 promoted the transformation of ZnO NPs into zinc phosphate (Zn-P) precipitates via interactions with dissolved Zn2+. However, P6-promoted ZnO NP dissolution was through the formation of soluble Zn-P complexes due to the strong capability of P6 to chelate with Zn2+. The transformation of ZnO NPs in the presence of P3 was affected by reaction time, pH, and P/Zn molar ratio. P3 first formed inner-sphere surface complexes on ZnO NPs, which gradually transformed into crystalline Zn2HP3O10(H2O)6 precipitates. This study provided a new perspective for understanding the reactivity of various forms of inorganic phosphate species with ZnO NPs in the natural environment.